1. Field of the Invention
The present invention relates to an apparatus for feeding a continuous slide fastener chain having strips of fabric attached to one or both outer edges thereof into a subsequent processing station.
2. Description of the Prior Art
In the mass-production of garments, bags, etc. having slide fasteners attached thereto as a closure for openings, it is customary to first sew strips of fabric successively to opposite edges of a continuous slide fastener chain at predetermined intervals. Then, the slide fastener chain with attached fabric strips is fed longitudinally into a subsequent processing station such as a slide-mounting station and a cutting station in which the slide fastener chain is severed transversely between the adjacent strips into a succession of slide fasteners of individual lengths. Finally, the fabric strips attached with the slide fasteners are processed or finished into garments, bags, etc.
One such known practice is disclosed in U.S. Pat. No. 4,989,851. The conventional apparatus according to this U.S. patent comprises a guide mechanism having a guide slit formed longitudinally therein and adapted for guiding a continuous slide fastener chain having strips of fabric attached thereto and a gripper for gripping the leading end of the slide fastener chain and dragging the slide fastener chain downstream to a subsequent cutting station in which the slide fastener chain is severed transversely between adjacent strips into a succession of slide fasteners of individual lengths.
Since having relatively heavy fabric strips attached thereto, the continuous slide fastener chain is subject to severe frictional resistance while it is dragged by the gripper. Consequently, the gripper cannot sometimes drag the slide fastener chain in proper posture, thereby causing the attached fabric strips to be caught in neighboring parts of the apparatus, so that smooth and stable feeding cannot be accomplished. If the things become worse and the severe frictional resistance surpasses the gripping force of the gripper, then, the continuous slide fastener chain is detached from the gripper.
Another such known practice is shown in U.S. Pat. No. 5,114,057. The conventional apparatus according to this patent comprises a pair of upper and lower guide members located upstream of a cutting station and defining therebetween a feed path to feed a continuous slide fastener chain with fabric strips through and a pair of feed rollers located on the middle of the guide members and holding the continuous slide fastener chain with attached strips therebetween, one of the feed rollers being connected with a drive means for advancing the continuous chain with attached strips downstream along the feed path to a subsequent cutting station in which the slide fastener chain is severed transversely between adjacent strips into a succession of slide fasteners of individual lengths. However, the frictional contact of the feed rollers against the slide fastener chain takes place only at a point at which the two feed rollers contact each other. As mentioned earlier, the continuous slide fastener chain having fabric strips attached thereto is considerably heavy and is thus subjected to severe frictional resistance. With both factors combined, the feed rollers can slip on the slide fastener chain and cannot fully and accurately transmit their rotating force to the slide fastener chain which thus cannot be fed in smooth and stable manner.